UPD784026 Renesas Electronics Corporation., UPD784026 Datasheet - Page 475

• Manufacturer Part Number: UPD784026
• Description: 16/8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

17.1 FUNCTIONS
(1) 3-wire serial I/O mode (MSB/LSB-first)
(2) Serial bus interface (SBI) mode (MSB-first)
17.2 CONFIGURATION
The configuration of the PD784026’s clocked serial interface is shown in Figure 17-1.
The PD784026’s clocked serial interface uses the following two operating modes:
The block diagram of clocked serial interface (CSI) is shown in Figure 17-1.
In this mode, 8-bit data transfers are performed using three lines: the serial clock (SCK0) and serial bus (SO0, SI0).
This mode is useful when connecting a peripheral
I/O device, display controller, etc., that incorporates a conventional clocked serial interface.
In the SBI mode, communication is performed with multiple devices by means of two lines: the serial clock (SCK0) and
the serial data bus (SB0).
This mode conforms to the NEC serial bus format.
In the SBI mode, it is possible to output to the serial data bus an address to select the target device for serial
communication, a command which gives a directive to the target device, and actual data. It is therefore possible to
eliminate the handshaking lines required when connecting multiple devices on a conventional clocked serial interface,
allowing efficient use of input/output ports.
CHAPTER 17 CLOCKED SERIAL INTERFACE
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